The present invention relates generally to footwear, and in particular the present invention relates to an automatic lacing system for an article of footwear.
Devices for automatically tightening an article of footwear have been previously proposed. Liu (U.S. Pat. No. 6,691,433) teaches an automated tightening shoe. The tightening mechanism of Liu includes a first fastener mounted on the upper, and a second fastener connected to the closure member and capable of removable engagement with the first fastener so as to retain releasably the closure member at a tightened state. Liu teaches a drive unit mounted in the heel portion of the sole. The drive unit includes a housing, a spool rotatably mounted in the housing, a pair of pull strings and a motor unit. Each string has a first end connected to the spool and a second end corresponding to a string hole in the second fastener. The motor unit is coupled to the spool. Liu teaches that the motor unit is operable so as to drive rotation of the spool in the housing to wind the pull strings on the spool for pulling the second fastener towards the first fastener. Liu also teaches a guide tube unit that the pull strings can extend through.